Distinct Source Water Chemistry Shapes Contrasting Concentration-Discharge Patterns

摘要: Author(s): Zhi, W; Li, L; Dong, Brown, Kaye, J; Steefel, C; Williams, KH | Abstract: Understanding concentration-discharge (C-Q) relationships are essential for predicting chemical weathering and biogeochemical cycling under changing climate anthropogenic conditions. Contrasting C-Q have been observed widely, yet a mechanistic framework that can interpret diverse patterns remains elusive. This work hypothesizes seemingly disparate driven by switching dominance of end-member source waters their contrasts arising from subsurface heterogeneity. We use data Coal Creek, high-elevation mountainous catchment in Colorado, recently developed watershed reactive transport model (BioRT-Flux-PIHM). Sensitivity analysis Monte-Carlo simulations (500 cases) show reaction kinetics thermodynamics distribution materials across depths govern the chemistry gradients shallow soil water deeper groundwater entering stream. The alternating organic-poor geo-solute-rich dry conditions organic-rich geo-solute-poor during spring melt leads to flushing pattern dissolved organic carbon dilution geogenic solutes (e.g., Na, Ca, Mg). In addition, extent concentration regulates power law slopes (b) via general equation (Formula presented.). At low ratios versus concentrations (C n=nC /C nln0.6), occurs; at high ngn1.8), arises; chemostasis occurs between. quantitatively interprets b values 11 (dissolved carbon, P, NO , K, Si, Mg, Al, Mn, Fe) three catchments (Coal Shale Hills, Plynlimon) differing climate, geologic, land cover indicates potentially broad regulation heterogeneity determining wide applications this quantifying values, which implications transformation scale. ratio sw gw 3 −